How about Xiaomi 20000 charging treasure?

Xiaomi 20000 mobile power supply still uses the white style packaging box of Xiaomi accessories, and the silver logo with the word mi is on the bottom of the front.

There are bar codes such as anti-counterfeiting labels and product serial numbers on the left.

On the right are product index parameters, such as production capacity, input-output parameters and production information.

Yellow security label and serial number bar code.

Index parameters of the product, battery capacity:19020/20000mah68.47/72wh (min/typ) output: 2*DC 5. 1V/2A MAX 338g input: dc5v/2a9v/2a12v//.

The main body of the mobile power supply is protected by plastic film, with a short charging cable, which is longer than Xiaomi 10400 and about 3 1.8cm long flexible flexible flat cable. It can also be used to transmit data. The interface adopts TPE soft glue, and the hand-held part adopts mirror polishing technology, and the details are handled in place. Some time ago, this data cable rice son went on the market, and there is one in 9.9 yuan.

Xiaomi 20000mAh mobile power supply is white, and the front millet logo is made of mirror material, which is different from the previous logo made by laser burning and made of plastic shell material. The overall shape is square, with arc transition at the edge, and the side edges are no longer semicircular sides of Xiaomi 10000mAh and 16000mAh. The weight of 338g is also a little lighter than that of 350g of 16000mAh.

See Xiaomi 20000 at a 45-degree angle. Considering the arrangement of the top two sockets, the power button is set on the side of the fuselage, which is rectangular with rounded corners, which is different from the round buttons on previous products.

See Xiaomi 20000 at an oblique angle of 45 degrees. This time, instead of using the aluminum alloy shell of the previous product, PC+ABS plastic environmental protection material is adopted, which can withstand the high temperature of 90℃. The surface is designed with gradual bumps, which is anti-slip and scratch-proof, and also reduces the weight. For a large-capacity mobile power supply, it is quite practical. Using plastic shell, drawing lessons from the previous purple rice fast charging mobile power supply, plus a large area of pcb heat dissipation, temperature should not become a bottleneck.

There are detailed product parameters at the bottom. Capacity, input and output parameters, production information.

There are two USB output ports and one Mirco USB input port at the top. It is worth mentioning that the two output ports of Xiaomi 20000mAh mobile power supply are arranged left and right, which is more friendly than the two parallel output ports of Xiaomi 16000mAh mobile power supply and more convenient for plugging and unplugging. Four power indicator lights are placed in the middle parallel to the charging port, and the indicator lights corresponding to the power percentage will flash to remind when charging and discharging.

The size of Xiaomi's 20000mAh mobile power supply (141.9 * 73 * 21.8mm) is the same as that of Xiaomi 16000mAh mobile power supply (154*60.4*22mm) released in the same period of last November.

Compared with stacking, there is one more cell, which greatly increases the volume.

One is the corner of an arc, and the other is a rectangle with a transition edge. Relatively speaking, the tenderloin of Xiaomi 16000 is more pleasing.

Compared with Xiaomi 16000, Xiaomi 20000 has a relatively spacious interface layout, a much more reasonable output interface and is very convenient to use because there is no switch on the bottom.

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Part II: Disassembly

There is no suspense. Millet 20000mAh uses 6 batteries 18650. This disassembly code is "LGABF 1L 1865" battery, and the capacity of a single battery is 3350mAh. Because Xiaomi 10000mAh mobile power supply has used this battery before, the charging head network is introduced in detail. Different from the discharge of Xiaomi 16000 and Xiaomi 10000 batteries, this time six batteries are placed side by side. The battery cell and the circuit PCB are placed side by side with a temperature probe. Xiaomi mobile power supply has always been protected by temperature probe, which is very kind.

The negative electrode of the battery has black cushioning cotton, which makes the battery core and the shell more fit.

The battery anode is insulated by paper, which greatly reduces the probability of battery short circuit. The positive electrode of the battery has black cushioning cotton, which makes the battery core and the shell fit better.

Battery with code "LGABF 1L 1865".

Battery cell data, cut-off charging voltage is 4.2V, discharge voltage is 2.5V, standard capacity is 3350mAh, and minimum capacity is 3240mAh. The maximum charging current is 0.5C( 1625mA).

In fact, the circuit scheme of Xiaomi 20000mAh mobile power supply is not much different from Xiaomi 16000. BQ24 195 is replaced by BQ25895 (in fact, the input voltage of this chip is 3.9- 17V), and there is little difference in other aspects.

The solution of Xiaomi 16000 was reviewed, and the charging and discharging scheme of TI BQ24 195 was adopted. Due to dual output, BQ24 195 is responsible for one output, and the silica gel SY7065A is responsible for the other output.

Because it supports fast charging input and does not support fast charging output, the scheme adopts single chip microcomputer and BQ25895 chip. Because of dual-port output, and the maximum 5V output of BQ25895 chip is 3. 1A, like Xiaomi 16000, one boosted output is processed by BQ25895 chip, and the other boosted output is processed by silica gel SY7065.

Side circuit board with micro USB interface.

Chip 25 13 under the left USB interface is a dual-channel intelligent identification chip, which supports the intelligent identification of two USB outputs;

Two R020 resistors are output current sampling resistors;

There is a 2N4B8 MOS near each of the two USB outputs, which is responsible for turning off the overload of one USB output.

Side circuit board without micro USB interface.

On the right, two 2n4b8s below R 100 and two 2N4B8 *** in the above figure constitute the protection board of the mobile power supply.

In the lower right corner of the circuit board is a protection chip, model: G4JC.

On the upper right of ABOV microcontroller is the regulated power supply chip of microcontroller, model: QBUON.

Responsible for the other output. In the picture, the screen printed on the right side of the left inductor is "Aa4EA", which is silicone SY7065.

TI BQ25895 chip, the index is good.

Introduction of BQ25895 chip.

Modern ABOV 97F 1204SMBN single chip microcomputer, packaged in SOP 16, the production cycle is 15, the 38th week. This MCU is responsible for the display of 20000mAh of millet, and cooperates with TI BQ25895 to realize temperature protection.

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Part III: Performance test

testing environment

(A) Mobile power output maximum current test

1. 5V over-current test of the output port at the switch button side: the maximum output current is 2.40A @5.06V, and voltage compensation is available when the output is1.20a.

2. 5V overcurrent test of the output port far away from the switch button side: the maximum output current is 2.40a @ 5.02 V. When the output is 1.20A, voltage compensation will be started. The output voltage is slightly lower than that of the other port.

3. Two-port combined 5V overcurrent test: the maximum output current is 3.50A@4.90V, and there is voltage compensation when the combined output is 1.90A, which is a little lower than the nominal maximum value of the product of 3.6A, which can be considered to be caused by the test instrument and environmental impact.

(II) Charging time test of mobile power supply

The charging test of Anker dual-port 5V charger for 1 and Xiaomi YDDYP0 1 20000 mobile power supply.

The mobile power supply will be automatically turned off, and the discharge current is 1A, and then the charging test will be conducted after standing for 10 minutes: the charging input voltage is 5V. From the charging curve, the charging current is not a smooth curve, and the current is constantly changing, similar to pulse charging. Finally, it takes time: after the mobile power supply is fully charged, the four indicator lights will not go out, which requires a certain amount of current. The turn-off current set by EBDUSB is less than that of LED lamp, so the instrument failed to stop recording automatically, but the accurate charging time can be calculated from the saved data as 36,346 seconds, that is, 606 minutes, 10. 1 hour. In the first 7 hours 19 minutes and 25 seconds, 84.29% of the electricity was charged. Simply calculate the charging capacity as 16858mah.

2.9V charging test with QC charger: the final time is 7 hours and 20 minutes. In the first 4 hours, 33 minutes and 59 seconds, 67.85% of electricity was charged, which is simply calculated as charging capacity 13570mah. Less charging in the later period, long time.

3. 12V charging test, charging test with our own purple rice charger HA5 1 1QC: correctly identify our own charger, shake hands with 12V successfully, and the charging input voltage is 12V. Judging from the charging curve, the charging current is not a smooth curve, and the current is constantly changing, which is similar to pulse charging and is finally used. In the first 3 hours, 37 minutes and 26 seconds, 73. 17% of electricity was charged, and the simple calculation is the charging capacity 14634mah, which requires less charging time and longer charging time.

(3) Mobile power output capability test

1, 5v 1A output capacity test on switch button side: output 12600mAh, 63.65WH, average voltage 5.05v. The output capacity is very close to the nominal 12700( 1A). Calculation conversion efficiency: 63.65/68.47=92.96% (close to the nominal 93%) and 63.65/72(TYP)=88.40%.

2. Test of key side 5v2A output capacity: output 1 1490mAh, 59.02WH, average voltage 5. 14V. Calculation conversion efficiency: 59.02/68.47=86.20% and 59.02/72(TYP)=8 1.97%.

3. The output capacity test of remote key side USB2 port 5V2A: output 1 1620mAh, 59.36WH, average voltage 5.11v.. Calculation conversion efficiency: 59.36/68.47=86.69%, 59.36/72(TYP)=82.44%. The output capacity and energy are a little more than the other output port.

Part IV: Compatibility Testing

This part of the test uses Xiaomi 20000 mobile power supply, charging with common terminals on the market, such as mobile phones and tablets. Although the output does not support QC2.0, charging Apple phones and tablets can reach high current. For example, charging iPad can reach 2A current, and matching Android phones can also approach the level of the original charger.

Use a charger that supports QC2.0 and only has 5V output to charge Xiaomi 20000 mobile power supply, in which 5V power supply can reach the maximum power of 10.686W, while power supply that supports QC2.0 12V, such as Meizu UP 1220, can reach the input power of 20.686W. Obviously, supporting QC2.0 input can greatly shorten Xiaomi 2000.

The fast charging mode cannot be negotiated with Anker Powerport+1A 2132 charger. This charger cannot negotiate the fast charging mode before Mizi HB8 10. Other fast charging chargers can negotiate to the fast charging mode.

The compatibility of output and input is good as a whole.

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Xiaomi 20000 mobile power supply has the following advantages:

1, large capacity, 20000mAh capacity, no loss of strength, can output more energy;

2. The workmanship is meticulous, the edge of the shell is smooth and burr-free, the input and output ports are arranged reasonably, and the non-slip surface is adopted;

3. Support QC 2.0 input, which is acceptable for its own charging speed; 4. The output efficiency is high, and TI 25895 and SY7065 are used to ensure the efficiency.

Disadvantages:

1, does not support QC 2.0 output, only supports 5V output;

2, the appearance is mediocre and the value is average;

Personal opinion: Xiaomi 20000 is a mediocre product, which only supports fast charging input and does not support fast charging output. Not compared with other products, only compared with Xiaomi's own millet 10000; Xiaomi 20000 has a capacity of 20000mAh. With the fast charging head supporting 12V output, it can charge itself for more than 6 hours. In fact, there are two millet 10000 which can also reach the capacity of 20000mAh. It is portable and it takes more than five hours to charge a single meter. In terms of capacity and self-charging, Xiaomi 20000 has no advantage. Besides, in terms of price, a millet is priced at 149 and a millet at 10000 is priced at 69. Even if you buy two millet 10000, it is more cost-effective than a millet of 20000.

Personal suggestion: Xiaomi should build a mobile power supply with a capacity of 10000mAh, which supports fast charging input and output and is priced at 99 yuan. The solution is still Xiaomi's handy TI chip. With other boost and identification chips, the appearance can follow the style of Xiaomi 10000. Or the current Xiaomi 16000 is replaced by a 3350 battery, which supports fast charge input and output. Price 149 yuan, cost-effective is self-evident.